There is a general agreement among scholars who study human behaviour in believing the primary function of language to be that of vocally carrying out the "social tendency to see reality in a symbolic way" (Sapir, 1935). Experiments on the acquisition of concepts and categorization have proved that language knowledge is more intuitive than other types of knowledge such as, for example, knowledge of inter-personal transcriptions. Indeed natural languages are not only system of signification in human societies, but they exist together with other non-verbal sign systems. The importance of verbal language and its central position within the communication system make it a capital tool for the co-ordination of subjective 'vital space', with a more and less direct reference to the objective social field.
